Dual differential control valve



April 15, 1969 w. F.JEHN i 3,438,395

DUAL DIFFERENTIAL CONTROL VALVE Filed Feb. 16. 1967 INVENTOR. WEKA/6,6F3 df/ ,grrof :is

United States Patent O 3,438,396 DUAL DIFFERENTIAL CONTROL VALVE WernerF. Jehu, 438 T winning Drive, Dayton, Ohio 45431 Filed Feb. 16, 1967,Ser. No. 617,768 Int. Cl. FlSb 3/00; C03b 9/02 U-S. Cl. IS7-596.18 8Claims ABSTRACT OF THE DISCLOSURE A control valve for glass-blowingapparatus comprising a sealed casing having a cylindrical ring supportedin slaid casing with spaced parallel flexible diaphragms closing theopposite side faces of said ring to form an isolated pressure or suctionresponsive chamber between said diaphragms, A positive or negativepressure intake conduit in communication with the interior of saidisolated pressure responsive chamber adapted to be supplied withpositive or negative (suction) oral pressure by the glassblower. Apositive pressure supply valve in said casing connected to one of saiddiaphragms and responsive to outward deflection of that diaphragm tosupply a positive pressure into said casing and a negative or suctionpressure control valve in said casing connected to the other diaphragmresponsive only to inward deflection of that diaphragm for applyingsuction or negative pressure to the interior of said casing. A iiexibleglass-blowing conduit connected in communication with the interior ofsaid casing for supplying the said positive or negative pressure fromthe interior of said casing to the molten glass article being blown inisolated responsive relation to the glassblowers positive or negativeoral pressures.

The invention described herein may be manufactured and used by or forthe United States Government for governmental purposes without thepayment to me of any royalty thereon.

Cross-references to related applications This invention is animprovement on my copending patent application for Oral ContnolledPressure Regulator, Ser. No. 537,616, led Mar. 21, 1966.

Summary of the invention The dual differential control valve comprisesmeans which permits the glassblower to isolate his breath from themolten glassware or article under fabrication by replacing his breathwith an inert or reducing gas under sensitive control of theglassblowers oral pressure or suc- The dual differential control valvecomprises means tion to protect the glassblower from harmful substancesduring the fabrication, such as radioactive material or mercury vaporsthat may be given off from the heated surfaces of his glasswork, and toprotect the glasswork being blown from being contaminated by themoisture or oxygen content of the glassblowerls breath.

An important object of the invention is the provision of asupersensitive control valve structure that will deliver `'an inert gasto the molten glasswork being fabricated at substantially the samerelative pressures that the glassblower applies to his glass-formingmouthpiece.

A further object includes means for supplying an isolated suctionpressure to the glasswork being blown at substantially the same pressureas the glassblowers suction pressure.

A further object is the provision of a glassblowing apparatus forsupplying either a positive or a negative isolated pressure medium to amolten glass article being blown under control of a glassblowerspositive or suction oral pressures in which the pressure or suction for3,438,396 Patented Apr. 15, 1969 fabrication of the molten glass articleis completely iso lated from the glassblowers oral breath pressure orsuction, and therefore permits the glassblower tomake full use of hisskill in creating and sensing the exact pressures needed forconstruction of the glassware or article, and also permits him to useboth hands for manipulating and forming the glassware. It alsofacilitates the glassblowers work in the fabrication of large volumeglasswork.

Brief description of the drawings FIGURE 1 is a somewhat diagrammaticelevation view, parts being broken away to foreshorten, illustrating saglassblowing apparatus incorporating the dual differential control valveof the invention and means for supplying positive or negative inert gaspressures to the glassblowing or forming tube and work being fabricatedunder direct control of the dual differential control valve.

FIGURE 2 is an enlarged detail vertical sectional view of the controlvalve structure of the invention, showing both valves in their normallygravity-closed position in full lines and showing the upper or positivepressure supply valve moved to open position in dotted lines to admitthe positive pressure of the inert gas to the glasswork being blown.

FIGURE 3 is a vertical sectional view similar to FIG. 2 but showing thelower or suction pressure inlet valve opened by the connected lowerdiaphragm, by the suction or negative oral pressure of the glassblower,to create a negative or suction pressure in the glasswork beingfabricated.

FIGURE 4 is a fragmentary det-ail sectional View taken about on line 4-4of FIG. 2.

Description of the preferred embodiments Reference numeral 1 denotes aclosed, leakpr-oof differential dual valve chamber or casing having abottom closure or valve supporting plate 2. The plate 2 is secured inplace by any suitable means (not shown) and adjacent the opposite sideedges of the plate are spaced parallel tubular conduits 3 and 4 whichextend through the plate 2 in sealed relation, extending upwardly withtheir upper ends curving inwardly toward each other as at 3a and 4a tosupport an upper or inert pressure inlet valve casing 5 which is locatedcentrally adjacent the top of the casing 1.

The tubular conduits 3 and 4 also Xedly support an annular orcylindrical ring 6 in parallel elevated relation to the base of thesupporting plate 2. The cylindrical ring 6 is supported fno-rn theconduits 3 and 4 by short tubular connections 7 and 8.

The upper end 3a of the conduit 3 opens in communication with theinterior of the inert pressure valve casing or chamber 5. The supportingconnection `8 for the right side of the ring 6 comprises a tubularconduit opening into the supporting conduit 4 at one end and intocommunication with the interior of the cylindrical ring 6, as shown.

Two thin tiexible rubber diaphragms 9 and 10, respectively, are tightlyfastened to the top and bottom peripheral edges of the ring 6, thussupporting the diaphragms 9 and 16 in spaced parallel relation to formwith the ring 6 an isolated leakproof chamber 11 which is connected incommunication with the interior of the conduit 4. The upper end of theinterior of the conduit 4 is closed.

The upper or inert pressure control diaphragm member 9 is reinforced byinside and outside discs 9a and 9b substantially as shown. The lowersuction or negative pressure control diaphragm 10 is 'also reinforced bythe plates 10a and 10b.

Each of the upper and lower diaphragms 9 Iand 1t) is respectivelyconnected by the upper and lower valve stems 1-2 and 13 to the discvalves 16 and 18. The inert pressure valve disc 16 normally seats bygravity on the valve seat 15 which surrounds the inert gaseous pressureinlet opening into the interior of the casing 1, pressure being admittedinto the valve chamber 5 from the pressure supply pipe 3 through theport 14.

The lower valve stem 13 extends downward from the diaphragm into a lowertubular conduit member 17 and carries a valve disc 18 which seats on anannular valve seat 19, the suction pressure passage 17C receiving thetransversely extending guide pins 18a on the lower end of the lowervalve stem 13.

The suction conduit 4member 17 extends downward and receives a flexiblehose 17a which is connected to a suction pump 17b having a dischargeoutlet pipe 17d. If the glassblower does not desire to apply suctionthen conduit 17 must be left open to atmosphere rather than connected tothe suction pump.

T-he valve stem 13 is thus stabilized in the enlarged bore or guidepassage 17C at one end and by the diaphragm 10 at its upper end.

The upper end of the upper valve stem 12 is likewise stabilized by thestem guide bushing 28 which extends downward in the upper valve casing 5as shown.

The main or supporting plate 2 has a fourth tubular conduit therethroughindicated at 21 which opens in communication with the interior of themain casing or shell 1 at its upper end while the lower end is providedwith a hose connection receiving a ilexible conduit or hose 22 which isconnected in communication with the molten glass manipulating andblowing tube of the glass-blower or glass-forming means 23.

The reference numeral 24 denotes a lump of molten glass on the outer endof the manipulating and blowing tube 23 at the start of theglass-blowing or fabricating operation. The inert pressure medium supplytube 3 extends downward through the plate 2 and out of the bottom of thecasing 1 and is connected by a flexible pressure supply conduit or tube25 through a suitable pressure regulator 26 of conventional design to asuitable source of inert gas under pressure, for instance supplied by apump or container 27.

The pressure medium which is supplied by the pump or tank 27 is providedat a relatively low pressure and is preferably a dry gas such asnitrogen, carbon dioxide, argon or forming gas at a low pressure ofabout 2 p.s.i.

The two diagram valve members 16 and 18 'are normally seated on theirrespective seats 15 and 19, and are held thereon respectively bygravity, aided by positive pressure supplied in the valve chamber 5through the conduit 3, and by the negative or suction pressure appliedin the lower valve guide bushing 17 from the suction putmp 17b. Thevalve is used in its vertical position as shown.

The glassblowers mouthpiece or nipple is indicated `at 28 and isconnected by a suitable length of flexible tubing 29 to the tube orconduit 4 projecting below the casing as seen in FIG. 1, whichestablished the glassblowers oral pressure or suction through the shortconduit 8 to the coniined and isolated space within the cylindrical ring6 and between the spaced valve controlling diaphragm members 9 and 10.

From the above it will be observed that if no pressure or suction isapplied through the mouthpiece 28 by the glassblower the isolatedpositive pressure on the disc valve 16 will not tend to open this valvewhile the suction or negative pressure in the tube 17 from the pump 17bwill not tend to open the disc valve 18 from its seat 19 since thepressure in the casing would be less than the pressure in the uppervalve casing 5 and would be greater than that in the lower tubularmember 17.

When the glassblower blows in the mouthpiece to iniiate or expand theglass bubble 24 this tends to separate the diaphragms 9 and 10, and atthe saime time forcing the lower disc 18 down tighter on its seat,raising the upper diaphragm 9 to move the valve disc 16 oit its seat.This allows the isolated gas pressure medium to enter the interior ofthe casing 1 and iiow through the conduits 21, 22 and 23 to expand themolten glass work 24 as desired. The amount of oral or breath pressureapplied by the glassblower determines the degree of opening of the valvedisc 16 and thus the rate of flow of the isolated inert gas to the workbeing blown. As soon as the pressure inside the casing 1, and also inthe glasswork, reaches the pressure which the glassblower appliesthrough his mouthpiece to the chamber 11, the diaphragm 9 will fall downagain by gravity and close the inlet valve 5. If the glassblower wantsto reduce the pressure inside the glasswork he releases some pressurefrom the chamber 11 through his mouthpiece. The greater pressure in thecasing 1 will open the valve 18 temporarily until pressure in chatmber11, casing 1 and work 24 is equalized then the valve 18 will drop closedby gravity.

Likewise when the glassblower applies suction to the mouthpiece 28 thereduced pressure in chamber 11 compared to pressure in the casing 1draws the upper diaphragm 9 down to firmly close the valve disc 16 onits seat 15 and suck the lower diaphragm 10 upwardly as seen in FIG. 3to raise the valve disc 18 olf its seat and the pressure medium in thecasing 1 and the tubing 21, 22, 23 and in the glasswork 24 will bewithdrawn to reduce the internal pressure when desired to contract theblown work 24. Varying the degree of suction by the glassblower variesthe suction area between the valve 18 and its seat which varies theeffective suction. When the negative pressure in chamber 11 and in theglasswork reaches the negative pressure the glassblower is applying tothe chamber 11 through his mouthpiece, the diaphragm 10 will fall downby gravity and close the valve 18.

Since the entire dual valve structure is carried rigidly by the bottomor supporting plate 2 the removal of the casing or shell for adjustmentexposes the entire internal working parts without disturbing theiroperative relations.

It is often desirable to keep a small ushing circulation of inert gasthrough the glass-'blown articles during the fabrication thereof, toprevent internal oxidizing by the atmosphere, especially when both ofsaid positive and negative pressure control valves are closed. This isimportant where the conduit 17 is open to atmosphere (lower pressure) aswell as being connected to a positive suction means such as 17b.

Referring to the drawings, a small inert gas bypass passage 3a isprovided in the supporting plate 2 and extends in communication at oneend with the positive inert gas pressure supply conduit 3, which asbefore mentioned, has a predetermined regulated low pressure of about 2p.s.i. This bypass passage or conduit 3a extends into the supporting orbase plate and turns upwardly to provide a needle valve controlledoutlet port 3b opening into the interior of the casing, the port 3bbeing controlled by the needle valve 3c which has a knurled adjustingwheel or disc conveniently located below the bottom of the supportingplate. Adjustment of the thumb wheel of course axially adjusts theneedle Valve to control the ow of the inert gaseous pressure mediumthrough the port 3b, which ow must necessarily be very small. Thisbypass out-iiow from the port 3b through the conduit 21, to the moltenglass articles being fabricated, prevents the atmosphere from enteringthe interior of the work and causing oxidizing, when for instance, atubular glass conduit member is being heated and manipulated by theglassblower to fuse the same into the side of another glass member toprovide a tubular bypass, or vent passage or the like. This bypassthrough the port 3b is necessarily very low, so as not to build upsutiicient undesirable pressure in the molten glass parts beingfabricated or joined, to prevent them from expanding, swelling orblooming by internal gaseous pressure while the two diaphragm valves 16and 18 are closed. This bypass pressure must be suiiiciently low toprevent pressure build up in the casing 1 sutiicient to open the valve18 by lifting the diaphragm.

I claim:

1. A dual differential pressure control valve device for glass-blowingapparatus comprising a closed pressure-tight casing; a positive andrelatively low pressure supply conduit, in communication with theinterior of said casing, adapted to be connected to a moltenglass-blowing device for applying positive or relatively low pressurefrom the interior of said casing to said molten glass-blowing device;positive pressure control valve means, fixed in said casing, having anoutlet port opening into said casing controlled by said valve means;spaced relatively low pressure control valve means, xed in said casing,having a relatively low pressure port opening into said casing,controlled by said relatively low pressure control valve means; spacedpositive and relatively low pressure actuated diaphragm means iixed insaid casing between said positive and relatively low pressure controlvalve means; a common positive and relatively low pressure supplyconduit means, connected to both of said positive and low pressureactuated diaphragm means, for simultaneously applying positive orrelatively lower pressure than the pressure in said casing to both ofsaid diaphragm means; said last mentioned conduit means extending out ofsaid casing and adapted to be connected to a glassblowers oral positiveor relatively low oral breath pressure applying means; an actuatingconnection, between said positive pressure diaphragm means and saidpositive pressure supply valve means, for opening said positive pressuresupply valve means into communication with the interior of said casing;a second independent actuating connection, between said relatively lowpressure control diaphragm means and said relatively low pressurecontrol valve means, operable to selectively open said relatively lowpressure control valve means in communication with said casing, whenpressure in said relatively low pressure diaphragm means is reducedlower than the pressure in said casing to reduce the pressure in saidcasing, for reducing the pressure in said outlet conduit means to saidmolten glass-blowing device.

2. A dual differential pressure control device for molten glass-blowingapparatus comprising a pressure-tight casing; a positive or negativepressure delivery conduit, in communication with the interior of saidcasing, adapted to be connected to a molten glass-blowing conduit forsupplying positive or negative pressure from the interior of said casingto said molten glass-blowing conduit; positive pressure control valvemeans, fixed in said casing, having a positive pressure outlet portopening into said casing controlled by said control valve means; spacedrelatively negative pressure control valve means, fixed in said casing,having a negative pressure conduit extending out of said casingcontrolled by said negative pressure control valve means, and adapted tobe connected to a negative pressure supply means; an annular dualdiaphragm supporting ring, fixed in said casing, in spaced relationbetween said positive and negative pressure control valve means; spacedparallel fiexible diaphragm members, secured to and closing both sidesof said supporting ring to form a closed isolated positive and negativepressure applying chamber therein; a glassblowers positive and negativesuction pressure application conduit connected in communication with theinterior of said charnber, between said diaphragms, and extending out ofsaid casing, adapted to be connected to a glassblowers oral positive orsuction pressure tubular conduit means for supplying isolated positiveor negative `glassblowers oral breath pressure into said ring betweensaid diaphragms; said diaphragms comprising a positive pressure actuateddiaphragm adjacent said positive pressure supply valve means and anegative pressure actuated diaphragm adjacent said negative pressurecontrol valve means; actuating means, connected between said positivepressure actuated diaphragm and said positive pressure control valvemeans, for opening said positive pressure control valve means by outwarddeflection of said positive pressure actuated diaphragm, by introductionof positive isolated oral pressure from the glassblower into saidchamber; and an operating connection, between said negative pressureactuated diaphragm and said negative pressure control valve means, 'foropening said negative pressure control valve means by application ofrelative suction or negative oral pressure through said positive andnegative pressure supply conduit by the glass lblower in said chamber tolower the pressure in said chamber below the pressure in said casing,for reducing the pressure in said casing and through said moltenglass-blowing conduit to said work being blown.

3. A dual differential pressure control device for manually controlledglassblowing apparatus comprising a closed casing having a moltenglass-blowing and fabricating outlet port; a dual diaphragm chamber,fixed in said casing, comprising an annular supporting ring and parallelspaced iiexible diaphragms closing both sides of the ring to form aclosed isolated pressure and suction applying chamber; a positive andnegative pressure supply conduit extending into said casing incommunication with the interior of said chamber, adapted to be connectedto a glassblowers oral breath pressure or suction tubular conduit supplyexteriorly of said casing for applying the glassblowers positivepressure or negative suction pressure into said chamber on saiddiaphragms; a normally closed positive pressure control inlet valve insaid casing adapted to control supply of positive pressure into saidcasing exteriorly of said chamber when said valve is opened; a positiveactuating connection between said positive pressure inlet valve and oneof said diaphragms for opening said positive pressure inlet valve byoutward defiection of said one diaphragm when the glassblowers positivebreath pressure introduced in said chamber exceeds to a predeterminedextent the pressure in said casing exteriorly of said chamber, forincreasing the pressure in said casing delivered through the saidchamber outlet port; a suction pressure outlet port in said casingadapted to be connected to suction applying means exteriorly of saidcasing; a suction pressure control valve in said casing normally closingsaid suction pressure outlet port; connecting means from said suctionpressure control valve connected to the other diaphragm to open saidsuction outlet port by inward deflection of said other diaphragm towardsaid chamber when suction applied within said chamber by the glassbloweris reduced to less than the internal pressure in said casing exteriorlyof said chamber, to reduce the pressure in said casing and through saidmolten glassblowing and fabricating outlet port to the glasswork beingfabricated.

4. A dual differential positive and negative pressure control device fororal glass-blowing apparatus comprising a supporting plate and covertherefor forming a closed positive or negative pressure enclosingcasing; a tubular positive and negative pressure supply conduit, lixedin said plate, leading outwardly from the interior of Said casing,adapted to be connected to a molten glass-blowing and manipulating tubefor blowing and fabricating molten glass articles; a suction applyingconduit fixed in said supporting plate for communication with theinterior of said casing, adapted to be connected exteriorly of saidcasing to a source of suction pressure; a suction pressure control valvein said Casing normally closing said suction conduit; a positivepressure Supply conduit fixed in said plate for supplying a positivepressure into said casing, adapted to be connected exteriorly of saidcasing to a source of predetermined positive pressure; normally closedpositive pressure control valve means in said casing normally closingsaid positive pressure supply conduit fixedly supported by said positivepressure supply conduit in spaced opposed aligned relation to saidsuction pressure control valve; a glassblowers positive oral pressureand suction applying conduit fixed in said plate and extending into saidcasing in closed fixed supporting relation to said positive pressurecontrol valve means, and extending out of said casing, adapted to beconnected to a glassblowers oral pressure and suction supply conduit forselectively applying positive oral pressure or suction to said positivepressure and suction applying conduit; a cylindrical dual diaphragmsupporting ring tixedly supported in said casing by said last mentionedconduit, between said positive pressure control valve means and saidsuction control valve; spaced first and second parallel flexiblediaphragms sealed to the opposite sides of said ring to form an isolatedpositive and suction pressure chamber therebetween; a communicatingpassage connected between the interior of said chamber and theglassblowers oral pressure and suction applying conduit means forincreasing the pressure in said chamber above the pressure in saidcasing to ex said first one of said diaphragms outward relative t saidchamber, or reduce the pressure in said chamber relative to pressure incasing to flex said second one of said diaphragms inward toward thechamber; a positive operating connection, between said first diaphragmand said positive pressure inlet control valve, tor opening said inletcontrol valve proportionally to the degree of outward deliection of thatdiaphragm; a positive actuating connection, between said seconddiaphragm and said suction inlet valve, for opening said suction inletvalve in proportion to inward deflection of the second diaphragm.

5. A device as set forth in claim 4, including7 a restricted positivepressure bypass conduit, connected between said positive pressure supplyconduit and the interior of said Casing, for supplying positive pressureinto said casing while the aforesaid positive pressure and suctioncontrol valves are closed; including pressure flow regulating means insaid `bypass passage for regulating the flow of positive pressure fromsaid positive pressure supply conduit into said casing.

y6. A dual differential pressure control device for molten glass-blowingapparatus comprising a closed casing having a bottom closure plate; apositive pressure supply conduit, ixed in said plate and extendingupwardly, having a central positive pressure outlet opening facingdownwardly into said casing, and adapted to be connected to positivepredetermining pressure supply means exterior of said casing; a relativenegative pressure conduit in said plate opening upwardly in said casingin vertically spaced aligned relation below said positive pressuresupply opening, and opening outwardly at its lower end away from thecasing; a relatively negative pressure control valve in said casing, inaligned spaced relation below said positive pressure supply conduitoutlet; a closed dual diaphragm chamber, -ixedly supported in saidcasing, comprising a cylindrical supporting ring intermediate saidpositive pressure and relatively negative pressure control valves; aglass blowers positive and relatively negative oral pressure supplyconduit fixed in said plate in supporting open communication with saidchamber; said glassblowers oral positive pressure and negative pressuresupply conduit extending through said plate outwardly away from saidcasing and adapted to be connected to a glass-blowers mouthpiece; apositive pressure responsive iirst diaphragm closing the upper side ofsaid chamber, deliectable upwardly by application of glassblowerspositive oral pressure introduced into said chamber; a relativelynegative pressure responsive second diaphragm comprising a lower wall ofsaid chamber, facing downwardly toward said relatively negative pressurecontrol valve, detiectable upwardly and inwardly of said chamber byapplication of relative negative glassblowers breath pressure in saidchamber; a positive operating connection, between said positive pressureresponsive first diaphragm and said positive pressure control valve, forOpening said last mentioned valve by upward deflection of said lastmentioned diaphragm; a positive operating connection between saidrelatively negative pressure responsive second diaphragm and saidrelatively negative pressure responsive control valve, for opening saidlast mentioned valve by upward deflection of the last mentioneddiaphragm incident to application of the glassblowers oral negativepressure in said chamber which pressure in said chamber is reduced lowerthan the pressure in said casing.

7. A device as set forth in claim 6, in which said positive pressuresupply conduit and said glass'blowers positive and relatively negativepressure supply conduit extend upwardly in spaced parallel fixedrelation from said bottom closure plate at opposite sides of the edge ofsaid chamber, and curve inwardly adjacent the top of said casing towardeach other with the upper ends thereof ixedly supporting said positivepressure control valve; and a positive supporting connection between theopposite sides of the dual diaphragm chamber and each of the lastmentioned conduits.

8. A device as set forth in claim 7, including a regulatable restrictedbypass conduit, between said positive pres sure supply conduit and theinterior of said casing, for feeding and regulating a limited pressureiluid bleed from said positive pressure supply conduit into said casing,to maintain a predetermined low positive pressure fluid ow out of saidcasing through the molten glassblowing and fabricating tube when both ofsaid positive and relatively negative pressure control valves are closedby lack of glassblowers positive or relatively negative pressure in saidchamber between said diaphragms.

References Cited UNITED STATES PATENTS 2,286,282 6/1942 Joesting137-5961 XR 2,825,361 3/1958 Selvos 137-596.18 2,966,927 1/1961 Peters137-596.18 3,052,064 9/1962 Kaeser 65-300 3,181,563 5/1965 Gitfen 65-301XR WALTER A. SCHEEL, Primary Examiner.

R. I. SMITH, Assistant Examiner.

U.S. Cl. X.R.

